A major objective of using a water blended fuel is to lower NOx (nitrogen oxides) emissions. In internal combustion engines, such as typical diesel engines for on-road vehicles, combustion temperatures usually approach about 2000° C. Under these conditions, the majority of the NOx produced is from oxidized atmospheric nitrogen that is pulled into the engine's manifold. On the other hand, combustion occurs at lower temperatures in open-flame burners such as in industrial boilers. At such lower temperatures, lower amounts of atmospheric N2 are oxidized and most of the NOx produced by such burners results from nitrogen introduced via the fuel and fuel additives.
Current commercial water blended fuel additive formulations, which are formulated for use in internal combustion engines contain on the order of 1000-1500 ppm nitrogen. The base fuel typically introduces about 100 to about 300 ppm nitrogen with the remainder coming from the additives. A significant portion of the nitrogen contributed to these fuels comes from surfactants which are used to stabilize the water blended fuels.
The problem, therefore, is to provide nitrogen-free surfactants for use in applications where nitrogen level is an issue, such as industrial boilers. Low nitrogen content may also become a factor in internal combustion engines as NOx emission levels are expected to be significantly lower by 2007.
This invention provides a solution to this problem by providing a water blended fuel composition containing a nitrogen-free surfactant. These fuels may be used advantageously in open-flame burners such as industrial boilers. These fuels are also useful in internal combustion engines.